This invention relates to a hydraulic damper particularly adapted for use in a suspension system of such as an automotive vehicle. A conventional hydraulic damper comprises a cylinder, a piston slidably disposed in the cylinder and partitioning the interior of the cylinder into two liquid chambers, a piston rod connected to the cylinder and extending out of the cylinder through one end thereof, a device for generating damping force in the extension stroke of the damper and a device for generating damping force in the contraction stroke of the damper. Various types of damping force generating devices have been proposed to generate desired damping force in relation to the speed or the displacement of the piston in the cylinder.